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ISO1541: Using higher channel count digital isolator for I2C

Part Number: ISO1541

Hi Team,

In my system, I am currently using multiple I2C ISO1541 digital isolators. Since I am using multiple isolators, I am curious if I can consolidate these isolators and use a non-specific digital isolator with higher channel count for multiple I2C signals?

Can you only use a specified I2C isolator if your signal is I2C?

If it is ok to use a non-specific digital isolator with higher channels count for multiple I2C signals, can you please recommend a device for me?

Thank you,

Jared

  • I²C signals are bidirectional and open-drain. You can use any isolator that supports these properties (which means none but the ISO154x).
  • Hi Jared,

    A digital isolator of higher channel count can be used for isolating I2C signals. Please refer to following document to understand the implementation of such circuits.
    http://www.ti.com/lit/an/slyt403/slyt403.pdf

    Since the clock is unidirectional in ISO1541, three digital isolator channels would be required to isolate one pair of SCL and SDA line. Refer to Figure 5 of the document to see the circuit diagram for the same. Using such techniques, any standard digital isolator like the ISO774x family of digital isolators can be used to achieve industry leading isolation specifications while isolating I2C signals.

    Hope this helps in answering your query, let us know if any additional explanation is required.

    Regards,
    Anand Reghunathan

  • Hi Jared

    Can you please share your mail-id. I wanted to understand few aspects of your system and need for multiple Isolated I2C channels.

    Best regards,

    Vikas Thawani